Clip, pluck, or let alone? Mint plant got black tips at new shoots where new growth is on most plants. Very tip center. Also, leaves started browning. Now the initial leaf spots weren't a concern because I thought the floral plastic caused it, from being pressed against plastic. It was a gift so I waited a couple days to cut it off. Now plant looks worse! Looks like rust? Maybe only been a week...couple days on and off. I bought a potted mint plant from a grocer supposedly from local grower. Not in with watered produce. Yet I saw some darker spots initially in store. It had floral plastic around neck of plant said to remove and place in 1/4 to 1/2"of water as it is hydroponic (yet, in a pot of soil that will sit in untrained pot).
Mint Plant in Floral Plastic Turned Brown
Certified GKH Gardening Expert
The black spots were likely due to improper watering. Overhead watering left spots on the leaves, that can cause leaf damage or disease.
You can cut or pinch the plant back and provide a good sunny spot.
Make sure the soil is moist but never soggy.